Tube coupling



May l0, 1949.

H. D. STECHER ETAL TUBE COUPLING Filed Jan. 18, 1946 'ffl/IWI.

wif-aw 33 34 l/// [ll/Mx INVEN T ORS HENRY .D SrEc//EP EL MER FJAC/rMAA/Qea listen-ted hay fanno Henry D. Stecher,

Jackman, deceased, 1 Helen E. Jackman,

Mich.; laid Stecher assignerl head' Company, Cleveland, Ohio,

` ofOhio Lakewood. om, and

late of Lakewood, h10, by.

admin trix tra Lansing, to The Weathera corporation y ApplicationJanuary 18, )1946, SerlaiNo. 642,018 '3 Claiml. (CL 285-167) connectors.

object of ou-r invention is to provide an im.

proved method and device for coupling smooth surfaced tubes.

Another object of our invention is to make both a mechanical connectionand a leak-proof seal with a smooth surfaced'tube. v

A'further object of our invention is to provide for Ioining mechanicallyand sealing smooth surfaced tubes without special tools.

A further object is to provide a joint in which guidi pressure assistsin making the joint leak-l Other and further objects, features andadvan' tages of the invention will become apparent as the descriptionproceeds.

In carrying out they invention in accordance witha preferred formthereof, a tting or body with an O-ring type -of seal is employed .forproducing a leak proof joint, a tube nut with means for mechanicallyengaging the tube is employed for securing the tube mechanically in thebody and a relatively st iii ring disposed in the Q-ring seal isemployed for preventing extrusion of the relatively soft 0ring or gasketthrough the clear- :me between the body and the tube joined there- Abetter understanding of the invention will be afforded by the followingdetailed description considered in conjunction with the accompanyingdrawing, in which Fig. 1 is a view partially in longitudinal medialsection of a tube coupling forming an embodiment of my invention;

Fig. 2 is an enlarged fragmentary sectional view of a portion of theapparatus of Fig. 1;

Fig. 3 is a fragmentary sectional view corresponding to Fig. 2,illustrating the use of a sealing ring nearly iilling the groovetherefor and 2 sponding to 5 illustrating a cutting ring of a differenttype; and

Fig. 8 is a detail view of in Fig. '1.

Like reference characters are utilized throughout the drawing todesignatelike parts. v

Referring to. Figs. 1 and`2, the arrangement there shown'by way ofillustration, comprises a tube-receiving body I I for receiving anunthreaded tube I2 and a tube nut I3 for securing the tube I2 in thebody II. For enabling the tube I2 to be made mechanically secure in thebody II and readily detachable, the tube I2 is flared to form an annularrib I4 spaced from the end of the tube and adapted to be clamped betweenthe edge III of the body Il and the forward edge Il of the tube nut I3.

In order to provide a leak-proof seal between the tube I2 and the body II which may be made readilyl and which will not be damaged by thedetachability of the tube- I2, an O-ring type of seal is preferablyprovided comprising a ring I6 of resilient rubber-like materialoccupying an annular groove I1 in the body II.

There is a bore I8 in the body II serving as a continuation of thepassageway formed by the interior of the tube I2. Preferably, the bodyII is counter bored as indicated at I9 leaving a shoulder 2I whereby theend 20 of the tube I2 may be received in the counter' bore I9 and mayabut the shoulder 2|. In the arrangement illustrated, the body I I hasan internally threaded mouth 22 adapted to receive the tube-securingtube nut I3, but it will be understood that the invention is not limitedto the precise arrangement shown for the cutting ring shown securing thetube-nut I3 or tube-fastening device having a recess in which anextrusion preventing ring is located;

Fig. 4 is a fragmentary sectional view corresponding to Fig. 3l in whichthe sealing ring has a substantially circular cross-section with aquadrant removed to accommodate the extrusion-preventing ring;

Fig.v 5 is a view partially in longitudinal medial cross-section of atube-coupling employing a cutting ring for mechanically securing thetube in the fitting;

Fig. 6 is a side view of the cutting ring shown in Fig. 5;

Fig. 7 is a fragmentary sectional view correin the body II, or fordrawing the tube I2 into the body I I' against the shoulder- 2l oragainst the edge II) in the mouth of the body I I.

For ready insertion and detachability of the tube I2 in the counter boreI9 of the body II, the dimensions are preferably such that a slightclearance.23 is provided between the outer surface of the tube I2 andthe inner surface of the counter bore I9. In order to prevent thepressure within the bore I8 and within the tube I2 from forcing therelatively soft material of the gasket or sealing ring I6 into theclearance yspace 23, injuring the gasket and interfering withreadydetachability of the tube I2, a guard is preferablyv provided such as aring 24. The latter i's cornposed of metal or other relatively stiffmaterial such as a suitable plastic, for example, having across-sectional diameter greater than the depth of the clearance space23.

amasar As illustrated in Figs. 1 and 2 the annular groove I1 has asubstantially rectangular crosssection and the uncompressedcross-sectional shape of the sealing ring I6 is substantially circularso that sp-ace remains between the sealing ring I6 and the outer sidewall 25 oftheannular groove l1 for the guard ring orextrusion-preventing ring 24.

It will be understood that when the coupling is under pressure, thesealing ring I6 will tend to be deformed from lcircular cross-sectionland preferably the uncompressed diameter of the sealing ring I6 issomewhat greater' than the depth radially of the annular groove I1, sothat the insertion of the tube I2 in the counter bore I9 will also tendto distort the cross-sectional shape of the sealing ring I6. When thecoupling is under pressure, there will be a tendency fo-r the sealingring I6 to assume the shape shown in Fig. 2 in whichthe material tendsto be forced away from the corner 26 of the annular groove 25 and intothe two corners 21 and 28 nearest the throat I0 ofv the body II. Thepresence of the guard ring 24, however, prevents the extrusion of thematerial from the corner 28 into the clearance space 23. It will beunderstood that the ring 24 is prefer-f. ably of such a diameter as tomake a relatively close t around the o'uter surface of the tube I2.

As illustrated in Figs. 1 and 2 we have shown a sealing ring having anormal or undistorted cross-sectional shape which is approximatelycircular or it may be elliptical, but it will be understoodv that ourinvention is not limited to the precise arrangement illustrated. Forexample. if desired the sealing ring may have such a shape as to fillthe annular groove I1 substantially except for the space occupied bythe'guard ring. As illustrated in Fig. 3, a rela-tively rectangularcrosssectional sealing groove I1 may be provided having a gasket orsealing ring 3I of such shape that its cross section has substantiallysquare outer corners 32 and 33 filling these corners of the groove I1.An annular recess 34 is provided for receiving a guard ring orextrusion-preventing ring 35, which in this case may be of a somewhatlarger diameter than the corresponding extrusion-preventing ring 24villustrated in Figs. 1 and 2.

Although in connection with the arrangement of Fig. 3, we haveillustrated a sealing ring 3| having square corners with a recess 34 toaccommodate a relatively large diameter guard ring 35, it will beunderstood that our'invention is not limited to the use of a sealingring of the precise cross-sectional shape shown when it is desired toemploy a relatively large diameter sealing ring. Thus as illustrated inFig. 4, a sealing ring 35 may be employed having an undeformed crosssectional shape which is substantially circular with a recess 34provided in the form of a quadrant or a sector of the normal circularoutline of the cross section of the sealing ring 36 to receive the guardring or extrusion-preventing ring 35.

In the arrangement of Figs. 1 to 4, inclusive, the'smooth surfaced orunthreaded tubing I2 is specially prepared forvsecurement in" the bodyII in that a portion of the tube 'I2 is ared to form the rib I4.However, our invention is not limited to the use of specially preparedtubing in order to obtain both mechanical securement and leak-proofsealing of tubing in atube-receiving body. Thus, for example, asillustrated in Figs. and 7. a smooth entirely cylindrical'tube 31 may bereceived within a body or fitting 38 and provided, both withmechanicalsecurement' 4 and leak-proof sealing. As shown specically inFig. 5 the body 38 may be provided with a counter bore I3 for receivingthe entirely .cylindrical smooth surfaced tubing 31 with an O-ringsealing arrangement such as illustrated in Fig. 1 and anextrusionpreventing guard ring 24. In this case, a' cutting ring 33 isprovided for securing the tubing 31 in the counter bore I9.

The invention is not limited to the useof a `specific type of cuttingring, but the' ring 39 has for sake of illustration been shown as beingof the type having a re-entrant counter bore 4I with a sharpened innerforward cutting edge 42.

For receiving the cutting ring 39 and' causing the sharpened edge l4ithereof to cut into the outer surface of the tube 31, a tapered orflaring mouth 43 is provided in the tube-receiving body 38, such thatas'the tube nut I3 is drawn into the body 38. the forward edge 44thereof bears against the cutting ring 43 forcingit inward and causingthe forward edges thereof to vcontract whereby the sharpened edge 42 isforced inward or is forced to contract. cutting into the surface 31 andseating itself therein to produce a notch 45 preventing internalpressure from pulling the tube 31 out of the counter bore I9 in the body38.

It will be understood that our invention is not limited to the use ofthe specific type of cutting ring 39 illustrated in Figs. 5 and 6. Forexample, if desired, a cutting ring may be employed which bites into thetubing 31 at both the forward and rearward ends of the cutting ring orcutting vsleeve as illustrated by the notches 48 and 41 in the tube31shown in Fig. 7. In this case. a cutting ring 48 may be employedv havinga cross-sectional shape such as illustrated in Fig. 8 with a sharpenedforward edge 49 and a sharpened rearward edge 5I. For this type ofcutting ring it is unnecessary to provide the body I I with a mouthhaving a long flare. and the rounding of the edge I0 is sufficient tocause the forward edge 49 of the ring 48 to bite into the tubing 31. Forcausing the rear edge 5I of the ring 48 to bite into' the tubing 31, atube nut 52 may be provided having an inner forward edge 53 rounded asshown whereby axial movement of the nut 52 forces the edge 5I inward.

We have herein shown and particularly described certain embodiments ofour invention and certain methods of operation embraced therein for thepurpose of explaining its principle of operation and showing itsapplication. but it will be obvious to those skilled in the art thatmany modifications and variations are possible and we aim, therefore, tocover all such modifications and variations as fall within the scope ofour invention which is claims.

What is claimed is:v

1. In combination a bodyihaving a bore therei in, a tube received withinsaid bore, an annular groove with a cylindrical outer wall in said bodyaround the portionof Asaid bore receiving said tube with ano-ring sealin'said groove anda relatively stiff -ring within said groove betweensaid sealing ring and the side wall of said groove away from theinterior of said body for protecting said sealing ring against extrusionthrough the clearance between the bore of said body and the outersurface of said tube.

2. A tube coupling comprising a body having a fluid conductingpassageway including a generally cylindrical bore leading from one end vthereof for reception of the end of a tube, an internalgroove in saidbody at said bore, a shouldefinedv in the appendedv der formed in saidbody axially outwardly of said groove, a tube having its end snuglyreceived in said bore, clamp means associated with said body fortightening said coupling, relatively rigid tube retaining means carriedby said tube and clamped between said body shoulder and clamp means tomechanically retain said tube in the coupling against axial motion, anda rubber-like O-ring seal in said body groove, said seal engaging thebottom wall of said groove, the tube, and the side wall of said tubedisposed toward said one end of the body, there being clearancebetweenlsaid ring body and tube at the corner formed by said groove sidewall and tube, fluid pressure within said coupling urging said ring awayfrom the other side wall of said groove and into contact with said tubeand said one groove side wall to provide a fluid seal between said bodyand tube.

3. A tube coupling comprising a body havinga uid conducting passagewayincluding a generally cylindrical bore leading from one end thereof forreception of the end of a tube, an internal groove in said body at saidbore, a shoulder formed in said body axially outwardly of said groove, atube having its end snugly received in said bore, clamp means associatedwith said body for tightening said coupling, relatively rigid tuberetaining means carried by said tube and clamped between said bodyshoulder mechanically retain said tube in the coupling against axialmotion, a rubber-like O-ring seal in said body groove, said ringengaging the bottom wall of said groove, the tube, and the side wall ofsaid tube disposed toward said one end of the body, there beingclearance between said 6 ring body and tube at the corner formed by saidgroove side wall and tube, fluid pressure within said coupling urgingsaid ring away from the other side wall Vof said groove and-into contactwith said tube and said other groove side wall to provide a fluid sealbetween said body and tube, and a relatively rigid and continuousextrusion prevention ring disposed in said corner and pressed againstsaid body and tube by fluid pressure to block the clearance between thebody and tube.

HENRY D. STECHER.

HELEN E. JACKMAN,

. Administratr of the Estate of Elmer F. Jackand clamp means to Y man,Deceased.

' REFERENCES CITED The following references are of record in the lc ofthis patent:

UNITED STATES PATENTS

